The patent application JP 1998-300324A describes a device for treating and decomposition of sanitary organic wastes (feces, urine, and toilet paper), kitchen wastes, and manure from ranching operations. Said patent application, includes a device built of stainless steel which includes a decomposition chamber that is partially filled with a sawdust matrix, a mixing mechanism powered by an electric motor, an electric heating system to raise the temperature in the decomposition chamber, and an air extraction system to create circulation therein, from the inside of the lavatory to the outside. The decomposition chamber is parabolic in form protected by a stainless steel cover that also serves as a base and support for the mixing mechanism and motor that powers it. The mixing mechanism is placed lengthwise in the chamber. It is made of stainless steel and has a shaft which supports it, through radial bars, two coils found towards the center and at one of its ends, the shaft connects to a transmission which is in turn connected to an electric motor. The heating system is made up by a series of Teflon electrical resistors placed lengthwise and crosswise spaced equidistantly on the outside wall of the chamber and the action of the motor and activation of the heating system are controlled by a microprocessor. Said patent application (JP 1998-300324A) presents disadvantages for use in Mexico, as well as in other countries, due to the climatic and economic reality of these countries. Some of these disadvantages are described below:                The cost of manufacturing the bioreactor is high when using stainless steel as its building material. This makes the system inaccessible for the Mexican market; for this reason this patent application proposes innovations to the design of the decomposition chamber that allows a diversification of the building materials without putting the integrity of the chamber at risk when exposed to an elevated pH, salinity, or temperature, present therein.        The mixing system does not guarantee uniform distribution of the biodegradable organic wastes throughout the bioreactor chamber, which affects the capacity for degradation of the system due to the fact that the opening used to introduce the organic wastes is eccentric. As a result of an analysis of the mixture of the material introduced, this invention proposes a central opening to solve this problem.        Heating of the decomposition chamber is accomplished with electrical resistors attached to the decomposition chamber's external wall, but only part of the heat generated by the electric resistors is actually transferred to the sawdust matrix through the wall of the decomposition chamber, and the rest is lost to the exterior, which causes considerable repercussions in the cost to operate the system. In contrast, in the patent application here proposed, heating of the sawdust matrix is performed with a device located on the inside of the decomposition chamber which uses solar energy, and therefore does not require electric power to create heat.        
Patent application JP 3027823 (1998) also uses a heating system (electric), as in the previous patent application, which is used to accelerate biological reactions and to adjust the humidity content resulting in high energy consumption. The mixing system is vertically configured with horizontal arms in the bottom of the decomposition chamber, which support vertical curved blades. The arms contain air diffusers through which air is supplied to the sawdust matrix creating an atmosphere conducive to aerobic degradation.
Patent application JP 2006-263418A replaces the electric heating system with conventional and non-conventional electric power sources like solar, wind, and others with a solar heater connected to a supply tank that powers a heat transfer device placed on the exterior of the decomposition chamber wall and, similar to patent application JP 1998-300324A1, this placement of the transfer device is not efficient due to the resistance presented by the heat transfer chamber wall.
The background of the in-situ system for aerobic heat treatment of biodegradable organic waste, which is the object of this invention, is found in the technical reports of step I and II on the development of sustainable systems for water supply and purification in rural and urban zones, presented by Dr. Miguel Angel Lopez Zavala (technician in charge) during 2005; that includes in said research reports: an in-situ system for the differentiated treatment of domestic waste water, that includes a Bio-Health device imported from Japan because it was not possible to acquire this type of Bio-Health device in Mexico. But during research, it was possible to identify opportunities to improve the Bio-Health device acquired in Japan, which later gave rise to a additional line of research, that culminated in this patent application named: “In-situ system for aerobic heat treatment of biodegradable organic waste” that overcomes the deficiencies in the previous patent applications through the innovative design of the decomposition chamber and a device that makes the heat transfer more efficient and allows the reduction of the losses thereof, which makes it a new system for aerobic heat treatment of biodegradable organic waste.
The potential of the system which is the object of this invention lies in that it makes it possible to provide sustainable treatment of organic wastes, such as: sanitary wastes (feces, urine, and toilet paper); manure from cattle operations; meat wastes; traces of blood; organic wastes from restaurants, housing, food industry, and agro-industry; and organic sanitary wastes in rural and urban areas without access to water supply systems and sewage services.
The problems that the invention solves are:    a) With respect to systems for the management and traditional treatment of organic wastes:            In-situ treatment, consequently eliminating the cost for transportation of the organic wastes,        High biodegradation rates, thus systems are compact and easy to operate,        Recovery of nutrients contained in organic wastes in an easy, economical, and effective manner,        Generation of a compost rich in nutrients, that is easy and safe to handle and may be used as a fertilizer or as a soil conditioner,        It does not generate bad odors because it uses an aerobic biological process.        Allows the use of renewable energy for the operation of the system.        Does not require specialized personnel for its operation.            b) With respect to conventional sewage systems:            Holistic solution for full management of human excrement,        Does not require water for its operation, thus can be used in areas where there is no water supply or sewage system,        Reduces the biological contamination of bodies of water and soil with organic material, nutrients, pathogens, and micro-contaminants (medications and hormones),        Reduction in water consumption per inhabitant by approximately 30%,        Applicable in scattered rural communities where conventional water and gray water management systems would be a heavy financial burden,        Eliminates bad odors in the lavatory,        Makes the recovery of nutrients possible in a simple and economical manner.            c) With respect to similar sewage systems:            Low construction, operation, and maintenance costs,        Greater efficiency in mixing the sawdust matrix,        Use of alternative energy (solar, wind, to give just a few examples), for its operation,        Greater efficiency in the transfer of heat from the heating system,        Lower heat losses through the walls of the reactor tank.        